Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/46—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography characterised by the light-to-heat converting means; characterised by the heat or radiation filtering or absorbing means or layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/323—Organic colour formers, e.g. leuco dyes
  • B41M5/327—Organic colour formers, e.g. leuco dyes with a lactone or lactam ring
  • B41M5/3275—Fluoran compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/333—Colour developing components therefor, e.g. acidic compounds
  • B41M5/3333—Non-macromolecular compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/30—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using chemical colour formers
  • B41M5/337—Additives; Binders
  • B41M5/3375—Non-macromolecular compounds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/40—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used characterised by the base backcoat, intermediate, or covering layers, e.g. for thermal transfer dye-donor or dye-receiver sheets; Heat, radiation filtering or absorbing means or layers; combined with other image registration layers or compositions; Special originals for reproduction by thermography
  • B41M5/42—Intermediate, backcoat, or covering layers
  • B41M5/423—Intermediate, backcoat, or covering layers characterised by non-macromolecular compounds, e.g. waxes

Definitions

• the present invention relates to a thermosensitive recording material, and more particularly to the improvement of a thermosensitive recording material comprising a support material and a thermosensitive coloring layer formed thereon, containing a colorless or light-colored leuco dye and a color developer capable of inducing color formation in the leuco dye upon application of heat thereto through a thermal reaction.
• thermosensitive recording materials are provided with a thermosensitive coloring layer of which the main components are thermosensitive coloring components, on a support material such as paper, synthetic paper, or a plastic film, so that colored images are obtained by application of heat through a thermal head, thermal pen, laser beam, stroboscopic lamp, and the like.
• a thermal head thermal pen, laser beam, stroboscopic lamp, and the like.
• this material has wide-scale utilization, not only as recording materials for copying books and documents, but also as recording materials for use with computers, facsimile machines, ticket vendors, recorders, and the like, and as recording labels.
• thermosensitive recording materials have gained further widespread application as recording materials in parallel with the progress in, in particular, the systemization of product systems and point of sale (POS) systems for product data and sales control.
• POS point of sale
• the thermal color developing components used in this type of thermosensitive recording material usually comprise a coloring agent and a color developer capable of inducing color formation in the coloring agent upon application of heat thereto.
• coloring agents leuco dyes having, for example, lactone, lactam, or spiropyran rings, are employed, and as such color developers, organic acids and phenolic acid materials are employed.
• thermosensitive coloring layer does not demonstrate satisfactory light resistance in image areas and the background, specifically because of the reduction in image density and the extreme discoloration of the background upon long-term exposure to fluorescent light or sunlight, especially in the application of labels in the systemization of POS.
• an ultraviolet-ray-absorbing compound such as benzophenone, benzotriazole and salicylate
• thermosensitive coloring layer is commonly known as a method of improving the resistance to light.
• an ultraviolet-ray-absorbing compound such as benzophenone, benzotriazole and salicylate
• thermosensitive recording material with superior resistance to light, or more specifically, a thermosensitive recording material of superior reliability almost free from color fading in the image areas and discoloring of the background during long-term exposure to fluorescent light and sunlight.
• thermosensitive recording material comprising a support material, a thermosensitive coloring layer formed thereon, comprising as the main components a leuco due and a color developer capable of inducing color formation in the leuco dye upon application of heat, and a protective layer formed on the thermosensitive coloring layer, containing a benzotriazole derivative as an ultraviolet-ray-absorbing agent for improving the resistance to light of the images developed in the coloring layer.
• Another object of the present invention is to provide a thermosensitive recording material of the above-mentioned type which, in addition to the above-mentioned advantages, has the advantages of having excellent thermal head matching properties and being free from the adhesion to thermal head of the dust coming from the protective layer or from the thermosensitive coloring layer during thermosensitive recording.
• a modified protective layer comprising (a) an upper layer and (b) a lower layer which is positioned on the side of the thermosensitive layer and contains the above-mentioned ultraviolet-ray-absorbing agent.
• an ultraviolet-ray-absorbing benzotriazole derivatives is employed in the protective layer.
• ultraviolet-ray-absorbing benzotriazole derivatives conventionally known compounds, for example, compounds having the following formula are preferably employed: ##STR1## where R 1 , R 2 and R 3 each represent hydrogen, a halogen atom, an alkyl group, an aryl group or a cycloalkyl group.
• benzotriazole derivatives for use in the present invention may include, but is not restricted to, the following:
• any conventional leuco dyes for use in conventional thermosensitive recording material can be employed.
• triphenylmethane-type leuco compounds, fluoran-type leuco compounds, phenothiazine-type leuco compounds, auramine-type leuco compounds and spiropyran-type leuco compounds are preferably employed.
• fluoran compounds having the following general formula are suitable for use in the present invention: ##STR2## wherein R 1 and R 2 each represent an alkyl group or a clohexyl group, R 3 represents an alkyl group, a haloalkyl group or a halogen atom, and R 4 represents hydrogen or an alkyl group. It is preferable that the alkyl groups in the above formula have 1 to 8 carbon atoms.
• color developers for use in the present invention conventional developers that are employed in the field of thermosensitive recording materials, such as phenolic compounds, sulfur-containing compounds, esters, carboxylic acid compounds, metal salt compounds and amine compounds, can be employed.
• phenylthiourea derivatives having the following general formula are particularly suitable for use in the present invention: ##STR3## where X and Y each represent a halogen atom, an alkyl group or a haloalkyl group, and m and n each represent an integer of 0 to 3.
• phenylthiourea derivatives may include, but is not restricted to, N,N'-diphenylthiourea, 4,4'-diethylphenylthiourea, 4,4'-dibutylphenylthiourea, 4,4'-dichlorophenylthiourea, 3,3'-dichlorophenylthiourea, 3,3'-dimethylphenylthiourea and 3,3'-ditrichloro-methylphenylthiourea.
• thermosensitive coloring layer there can be contained one or more binder agents, fillers, surface active agents, thermofusible materials and lubricants.
• binder agents examples include water-soluble resins such as polyvinyl alcohol, hydroxyethylcellulose, methylcellulose, and isobutylene/maleic anhydride copolymer alkali salts; and latexes of polyurethane, styrene/butadiene copolymer and polyacrylic esters.
• fillers examples include inorganic fillers such as calcium carbonate, silica, titanium oxide, aluminum hydroxide, clay and talc fillers; and finely-divided organic fillers such as urea-formaldehyde resin filler and polystyrene filler.
• lubricants are higher fatty acids, the esters, amides and metal salts of higher fatty acids, and conventional waxes.
• the protective layer comprises a binder agent, the previously described ultraviolet-ray-absorbing benzotriazole derivative and a filler.
• binder agents are water-soluble resins such as polyvinyl alcohol, hydroxyethyl-cellulose, methylcellulose, and isobutylene/maleic anhydride copolymer alkali salt; and latexes of polyurethane, styrene/butadiene copolymer and polyacrylic esters.
• one or more fillers are contained, for example, inorganic fillers such as calcium carbonate, silica, titanium oxide, aluminum hydroxide, clay and talc; and finely-divided organic fillers such as urea-formaldehyde resin filler and polystyrene filler.
• inorganic fillers such as calcium carbonate, silica, titanium oxide, aluminum hydroxide, clay and talc
• finely-divided organic fillers such as urea-formaldehyde resin filler and polystyrene filler.
• lubricants such as higher fatty acids and the esters, amides and metal salts of higher fatty acids can be contained in the protective layer.
• conventional surface active agents can also be contained in the protective layer.
• thermosensitive recording material In preparing the thermosensitive recording material according to the present invention, an aqueous dispersion comprising as the main components a leuco dye, a color developer and a binder agent is applied to a support material such as paper, synthetic paper and the like, to form a thermosensitive coloring layer. After the coated thermosensitive coloring layer is dried, a protective layer formation liquid comprising as the main components a water-soluble resin, a filler and an ultraviolet absorbing benzotriazole derivative is coated on the thermosensitive coloring layer.
• a protective layer formation liquid comprising as the main components a water-soluble resin, a filler and an ultraviolet absorbing benzotriazole derivative is coated on the thermosensitive coloring layer.
• the amounts of the leuco dye, color developer and binder agent in the thermosensitive coloring layer are, respectively, 5 to 30 wt. %, 40 to 80 wt. %, and 2 to 20 wt. %. Further, it is preferable that the amount of deposition of the thermosensitive coloring layer be about 2 to 10 g/m 2 .
• the amounts of the water-soluble resin, filler and ultraviolet-ray-absorbing benzotriazole derivative in the protective layer be, respectively, 10 to 80 wt. %, 5 to 80 wt. %, and 5 to 60 wt. %.
• a preferable amount of deposition to form the protective layer is about 1 to 10 g/m 2 .
• the protective layer comprises an upper layer and a lower layer which is situated on the side of the thermosensitive coloring layer
• binder agents are water-soluble resins such as polyvinyl alcohol, hydroxyethylcellulose, methylcellulose, and isobutylene/maleic anhydride copolymer alkali salt; and latexes of polyurethane, styrene/butadiene copolymer and polyacrylic esters.
• fillers such as inorganic fillers such as calcium carbonate, silica, titanium oxide, aluminum hydroxide, clay and talc; and finely-divided organic fillers such as urea-formaldehyde resin filler and polystyrene filler.
• lubricants such as higher fatty acids and the esters, amides and metal salts of higher fatty acids can be contained in the upper layer.
• conventional surface active agents can also be contained in the upper layer.
• the lower layer comprises a binder agent and the ultraviolet-ray-absorbing benzotriazole derivative.
• the binder agent the same water-soluble resins as those employed in the upper layer can be employed.
• the protective layer comprises the above-mentioned upper layer and lower layer
• the amounts of the water-soluble resin and ultraviolet-ray-absorbing benzotriazole derivative in the lower layer be, respectively, 30 to 90 wt. %, and 5 to 50 wt. %
• the amounts of the water-soluble resin and filler in the upper layer be, respectively, 10 to 80 wt. % and 5 to 80 wt. %.
• a dispersion A-1, a dispersion B-1 and a dispersion C-1 were separately prepared by grinding and dispersing the following respective components in a ball mill until the average particles of the solid components became 5 ⁇ m or less.
• Dispersion A-1, dispersion B-1 and dispersion C-1 were mixed in a ratio by weight of 5:30:10, so that a thermosensitive coloring layer formation liquid was prepared.
• a dispersion D-1 and a dispersion E-1 were separately prepared by grinding and dispersing the following respective components in a ball mill until the particle sizes of the solid components became 5 ⁇ m or less.
• Dispersion D-1 and dispersion E-1 were mixed in a ratio by weight of 32:5.
• a cross linking agent for the polyvinyl alcohol namely, a polyamide-epichlorohydrin resin
• the mixture was then uniformly mixed, so that a protective layer formation liquid was prepared.
• thermosensitive coloring layer formation liquid was applied to a sheet of commercially available high quality paper (50 g/m 2 ) by a wire bar and was then dried, with a deposition of 0.5 g/m 2 on a dry basis, whereby a thermosensitive coloring layer was formed on the high quality paper.
• thermosensitive coloring layer formation liquid was applied to the thermosensitive coloring layer with a deposition of 4 g/m 2 on a dry basis by a wire bar, so that a protective layer was formed on the thermosensitive coloring layer.
• a thermosensitive recording material No. 1-1 according to the present invention was prepared.
• Example 1-1 was repeated except that the dispersion E-1 employed in Example 1-1 was replaced by a dispersion E-2 with the following formulation, whereby a thermosensitive recording material No. 1-2 according to the present invention was prepared.
• Example 1-1 was repeated except that the dispersion A-1 and dispersion B-1 employed in Example 1-1 were respectively replaced by a dispersion A-2 and a dispersion B-2 with the following formulations, whereby a thermosensitive recording material No. 1-3 according to the present invention was prepared.
• Example 1-1 was repeated except that the dispersion E-1 employed in Example 1-1 was replaced by a comparative dispersion E-1 with the following formulation, which corresponded to the dispersion E-1 from which the ultraviolet-ray-absorbing agent was eliminated, whereby a comparative thermosensitive recording material No. 1-1 was prepared.
• thermosensitive coloring layer formation liquid was prepared.
• the dispersion D-1 which was employed in Example 1-1 and the comparative dispersion E-1 which was employed in Comparative Example 1-1 were mixed in a ratio by weight of 32:5.
• a cross linking agent for the polyvinyl alcohol, a polyamide-epichlorohydrin resin was added in an amount equal to 30 wt. % of the amount of the entire polyvinyl alcohol in the mixture.
• the mixture was then uniformly mixed, so that a protective layer formation liquid was prepared.
• thermosensitive coloring layer formation liquid was applied to a sheet of commercially available high quality paper (50 g/m 2 ) by a wire bar and was then dried, with a deposition of 0.5 g/m 2 on a dry basis, whereby a thermosensitive coloring layer was formed on the high quality paper.
• thermosensitive coloring layer with a deposition of 4 g/m 2 on a dry basis by a wire bar, so that a protective layer was formed on the thermosensitive coloring layer.
• a comparative thermosensitive recording material No. 1-2 was prepared.
• thermosensitive recording materials No. 1-1 through No. 1-3 according to the present invention and the comparative thermosensitive recording materials No. 1-1 and 1-2 were subjected to the following tests to investigate the color development capability, fading under sunlight and fading under fluorescent light.
• the image density of a colored image area developed at 140° C. using a thermal gradient tester, D max , and the background density thereof, D min , of each sample of the recording materials were measured by a Macbeth densitometer.
• a colored image area developed at 110° C. using the thermal gradient tester and the background thereof of each sample were exposed to direct sunlight for 30 hours.
• the changes in the image density of the image area and the background density thereof were measured by the Macbeth densitometer.
• a colored image area developed at 110° C. using the thermal gradient tester and the background thereof of each sample were exposed to fluorescent light at 5000 lux for 240 hours.
• the changes in the image density of the image area and the background density of the background were measured by the Macbeth densitometer.
• thermosensitive recording materials according to the present invention have extremely superior resistance to light (fading from sunlight and from fluorescent light exposure), and when specific leuco dyes and developers are combined in the thermosensitive recording materials, in particular, in Examples 1 and 2, this effect is even more pronounced.
• the dispersion A-1, dispersion B-1 and dispersion C-1 (which were employed in Example 1-1) were separately prepared by grinding and dispersing the following respective components in a ball mill until the average particles of the solid components became 5 ⁇ m or less.
• Dispersion A-1, dispersion B-1 and dispersion C-1 were mixed in a ratio by weight of 5:30:10, so that a thermosensitive coloring layer formation liquid was prepared.
• the dispersion E-1 (which was the same as that employed in Example 1-1 was prepared by grinding and dispersing the following components in a ball mill until the particle sizes of the solid components became 5 ⁇ m or less.
• the above dispersion E-1 was added to 10% aqueous solution of polyvinyl alcohol in such a manner that the amount of the benzotriazole derivative (ultraviolet-ray-absorbing agent) contained in the dispersion E-1 was 0.5 parts by weight to 1 part by weight of the 10% aqueous solution of polyvinyl alcohol.
• a cross linking agent for polyvinyl alcohol namely, a polyamide-epichlorohydrin resin, was added in an amount equal to 40 wt. % of the entire amount of the polyvinyl alcohol in the mixture.
• the mixture was uniformly mixed to prepare a lower layer formation liquid was prepared.
• a dispersion d-2 was prepared by grinding and dispersing the following components in a ball mill until the particle sizes of the solid components became 5 ⁇ m or less.
• a cross linking agent for polyvinyl alcohol a polyamide-epichlorohydrin resin
• a cross linking agent for polyvinyl alcohol a polyamide-epichlorohydrin resin
• thermosensitive coloring layer formation liquid was applied to a sheet of commercially available high quality paper (50 g/m 2 ) by a wire bar and was then dried, with a deposition of 0.5 g/m 2 on a dry basis, whereby a thermosensitive coloring layer was formed on the high quality paper.
• the lower layer formation liquid was coated on the thermosensitive coloring layer with a deposition of 3 g/m 2 on a dry basis by a wire bar, so that a lower layer was formed on the thermosensitive coloring layer.
• thermosensitive recording material No. 2-1 according to the present invention was prepared
• Example 2-1 was repeated except that the dispersion E-1 employed in Example 2-1 was replaced by the dispersion E-2 (which was the same as the dispersion E-1 employed in Example 1-2) with the following formulation, whereby a thermosensitive recording material No. 2-2 according to the present invention was prepared.
• Example 2-1 was repeated except that the dispersion A-1 and B-1 employed in Example 2-1 were respectively replaced by the dispersion A-2 and the dispersion B-2 with the following formulations (which were respectively the same as the dispersion A-2 and the dispersion 13-2 employed in Example 1-3), whereby a thermosensitive recording material No. 2-3 according to the present invention was prepared.
• Example 2-1 was repeated except that the dispersion E-1 employed in Example 2-1 was replaced by the comparative dispersion E-1 with the following formulation (which was the same as the dispersion E-1 employed in Comparative Example 1-1), which corresponded to the dispersion E-1 from which the ultraviolet-ray-absorbing agent was eliminated, whereby a comparative thermosensitive recording material No. 2-1 was prepared.
• Example 2-1 was repeated except that the lower layer formed in Example 2-1 was eliminated, whereby a comparative thermosensitive recording material No. 2-1 was prepared.
• Example 2-1 was repeated except that the upper layer formed in Example 2-1 was eliminated, whereby a comparative thermosensitive recording material No. 2-3 was prepared.
• thermosensitive coloring layer formation liquid was prepared.
• the comparative dispersion E-1 (which was a dispersion prepared by eliminating [2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole]from the dispersion E-1) with the following formulation was prepared in the same manner as in Comparative Example 2-1.
• a cross linking agent for polyvinyl alcohol a polyamide-epichlorohydrin resin
• a polyamide-epichlorohydrin resin was added in an amount equal to 40 wt. % of the entire polyvinyl alcohol in the mixture.
• the mixture was uniformly mixed to prepare a lower layer formation liquid was prepared.
• the dispersion D-1 (which was the same as that employed in Example 2-1) with the following formulation was prepared in the same manner as in Example 2-3.
• a cross linking agent for polyvinyl alcohol a polyamide-epichlorohydrin resin
• a polyamide-epichlorohydrin resin was added in an amount equal to 40 wt. % of the entire polyvinyl alcohol. The mixture was uniformly mixed, so that an upper layer formation liquid was prepared.
• thermosensitive coloring layer formation liquid was applied to a sheet of commercially available high quality paper (50 g/m 2 ) by a wire bar and was then dried, with a deposition of 0.5 g/m 2 on a dry basis, whereby a thermosensitive coloring layer was formed on the high quality paper.
• the lower layer formation liquid was coated on the thermosensitive coloring layer with a deposition of 3 g/m 2 on a dry basis by a wire bar, so that a lower layer was formed on the thermosensitive coloring layer.
• thermosensitive recording material No. 2-3 was prepared.
• thermosensitive recording materials No. 2-1 through No. 2-3 according to the present invention and the comparative thermosensitive recording materials No. 2-1 through No. 2-4 were subjected to the following tests to investigate the color development capability, fading under sunlight and resistance to oil. In addition, the thermal head matching properties of each recording material were also inspected.
• the image density of a colored image area developed by application of a thermal energy of 0.85 mJ using a printing simulator (made by Matsushita Electronic Components Co., Ltd., D max , and background density thereof, D min , of each sample were measured by a Macbeth densitometer.
• a colored image area developed by application of a thermal energy of 0.71 mJ and the background thereof of each sample were exposed to direct sunlight for 30 hours.
• the changes in the image density of the image area and the background density of background were measured by the Macbeth densitometer.
• Cotton-seed oil was applied to the colored image area which was developed by application of a thermal energy of 0.71 mJ and the background thereof.
• the image area and background thereof were exposed to fluorescent light at 5000 lux for 24 hours. The changes in the image area and background were visually inspected.
• Thermal printing was carried out with a length of 1 m on each thermosensitive recording material under application of a thermal energy of 0.71 mJ using the printing simulator, so that the thermal head matching properties, specifically sticking to each recording material of dusty materials coming from recording material and adhering of such materials to the thermal head during thermal printing were investigated.
• thermosensitive recording materials according to the present invention have extremely superior resistance to light and oil, and the recording materials themselves are excellent in the thermal head matching properties.

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Heat Sensitive Colour Forming Recording (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26373857

Family Applications (1)

Country Status (3)

Cited By (15)

Families Citing this family (11)

Citations (1)

Family Cites Families (2)

• 1986
  • 1986-02-20 US US06/831,456 patent/US4663642A/en not_active Expired - Fee Related
  • 1986-02-21 DE DE19863605675 patent/DE3605675A1/de active Granted
  • 1986-02-21 GB GB08604373A patent/GB2171810B/en not_active Expired

Patent Citations (1)

Also Published As

Similar Documents

Legal Events